scholarly journals Cross talk between microRNA and epigenetic regulation in adult neurogenesis

2010 ◽  
Vol 189 (1) ◽  
pp. 127-141 ◽  
Author(s):  
Keith E. Szulwach ◽  
Xuekun Li ◽  
Richard D. Smrt ◽  
Yujing Li ◽  
Yuping Luo ◽  
...  
Keyword(s):  
Stem Cells ◽  
Epigenetic Regulation ◽  
Cross Talk ◽  
Adult Neurogenesis ◽  
Cell Biology ◽  
Polycomb Group ◽  
Stem Cell Biology ◽  
Proliferation And Differentiation

Both microRNAs (miRNAs) and epigenetic regulation have important functions in stem cell biology, although the interactions between these two pathways are not well understood. Here, we show that MeCP2, a DNA methyl-CpG–binding protein, can epigenetically regulate specific miRNAs in adult neural stem cells (aNSCs). MeCP2-mediated epigenetic regulation of one such miRNA, miR-137, involves coregulation by Sox2, a core transcription factor in stem cells. miR-137 modulates the proliferation and differentiation of aNSCs in vitro and in vivo. Overexpression of miR-137 promotes the proliferation of aNSCs, whereas a reduction of miR-137 enhances aNSC differentiation. We further show that miR-137 post-transcriptionally represses the expression of Ezh2, a histone methyltransferase and Polycomb group (PcG) protein. The miR-137–mediated repression of Ezh2 feeds back to chromatin, resulting in a global decrease in histone H3 trimethyl lysine 27. Coexpression of Ezh2 can rescue phenotypes associated with miR-137 overexpression. These results demonstrate that cross talk between miRNA and epigenetic regulation contributes to the modulation of adult neurogenesis.

The Role of Nucleophosmin In Hematopoietic Stem Cells and the Pathogenesis of Myelodysplastic Syndrome

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 95-95 ◽  
Author(s):  
Keisuke Ito ◽  
Paolo Sportoletti ◽  
John G Clohessy ◽  
Grisendi Silvia ◽  
Pier Paolo Pandolfi
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Myelodysplastic Syndrome ◽  
Cell Biology ◽  
De Novo ◽  
Stem Cell Biology ◽  
Hematopoietic Stem

Abstract Abstract 95 Myelodysplastic syndrome (MDS) is an incurable stem cell disorder characterized by ineffective hematopoiesis and an increased risk of leukemia transformation. Nucleophosmin (NPM) is directly implicated in primitive hematopoiesis, the pathogenesis of hematopoietic malignancies and more recently of MDS. However, little is known regarding the molecular role and function of NPM in MDS pathogenesis and in stem cell biology. Here we present data demonstrating that NPM plays a critical role in the maintenance of hematopoietic stem cells (HSCs) and the transformation of MDS into leukemia. NPM is located on chromosome 5q and is frequently lost in therapy-related and de novo MDS. We have previously shown that Npm1 acts as a haploinsufficient tumor suppressor in the hematopoietic compartment and Npm1+/− mice develop a hematologic syndrome with features of human MDS, including increased susceptibility to leukemogenesis. As HSCs have been demonstrated to be the target of the primary neoplastic event in MDS, a functional analysis of the HSC compartment is essential to understand the molecular mechanisms in MDS pathogenesis. However, the role of NPM in adult hematopoiesis remains largely unknown as Npm1-deficiency leads to embryonic lethality. To investigate NPM function in adult hematopoiesis, we have generated conditional knockout mice of Npm1, using the Cre-loxP system. Analysis of Npm1 conditional mutants crossed with Mx1-Cre transgenic mice reveals that Npm1 plays a crucial role in adult hematopoiesis and ablation of Npm1 in adult HSCs leads to aberrant cycling and followed by apoptosis. Analysis of cell cycle status revealed that HSCs are impaired in their ability to maintain quiescence after Npm1-deletion and are rapidly depleted in vivo as well as in vitro. Competitive reconstitution assay revealed that Npm1 acts cell-autonomously to maintain HSCs. Conditional inactivation of Npm1 leads to an MDS phenotype including a profoundly impaired ability to differentiate into cells of the erythroid lineage, megakaryocyte dyspoiesis and centrosome amplification. Furthermore, Npm1 loss evokes a p53-dependent response and Npm1-deleted HSCs undergo apoptosis in vivo and in vitro. Strikingly, transfer of the Npm1 mutation into a p53-null background rescued the apoptosis of Npm1-ablated HSCs and resulted in accelerated transformation to an aggressive and lethal form of acute myeloid leukemia. Our findings highlight the crucial role of NPM in stem cell biology and identify a new mechanism by which MDS can progress to leukemia. This has important therapeutic implications for de novo MDS as well as therapy-related MDS, which is known to rapidly evolve to leukemia with frequent loss or mutation of TRP53. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Effects of Naringin on Proliferation and Osteogenic Differentiation of Human Periodontal Ligament Stem Cells In Vitro and In Vivo

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Lihua Yin ◽  
Wenxiao Cheng ◽  
Zishun Qin ◽  
Hongdou Yu ◽  
Zhanhai Yu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Osteogenic Differentiation ◽  
Periodontal Ligament ◽  
Trabecular Structure ◽  
Control Group ◽  
Periodontal Ligament Stem Cells ◽  
Expression Levels ◽  
Proliferation And Differentiation

This study is to explore the osteogenesis potential of the human periodontal ligament stem cells (hPDLSCs) induced by naringin in vitro and in vitro. The results confirmed that 1 μM naringin performs the best effect and a collection of bone-related genes (RUNX2,COL1A2, OPN, and OCN) had significantly higher expression levels compared to the control group. Furthermore, a typical trabecular structure was observed in vivo, surrounded by a large amount of osteoblasts. These results demonstrated that naringin, at a concentration of 1 μM, can efficiently promote the proliferation and differentiation of hPDLSCs both in vitro and in vivo.

scholarly journals Maintenance of hemopoietic stem cells and production of differentiated progeny in allogeneic and semiallogeneic bone marrow chimeras in vitro.

1977 ◽  
Vol 145 (6) ◽  
pp. 1612-1616 ◽  
Author(s):  
T M Dexter ◽  
M A Moore ◽  
A P Sheridan
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Culture System ◽  
Adherent Cells ◽  
Cellular Mechanisms ◽  
Graft Versus Host ◽  
Proliferation And Differentiation ◽  
Bone Marrow Chimeras

A culture system is described in which bone marrow-derived adherent cells can support prolonged proliferation and differentiation of genetically incompatible stem cells and precursor cells. The results suggest that the reactive cells responsible in vivo for host transplantation resistance and for graft-versus-host disease are selectively lost or inhibited in such cultures, which may provide a vehicle for studying some of the cellular mechanisms involved in transplantation resistance.

scholarly journals Human Fetal Bone Marrow-Derived Mesenchymal Stem Cells Promote the Proliferation and Differentiation of Pancreatic Progenitor Cells and the Engraftment Function of Islet-Like Cell Clusters

2019 ◽  
Vol 20 (17) ◽  
pp. 4083
Author(s):  
Xing Yu Li ◽  
Shang Ying Wu ◽  
Po Sing Leung
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Progenitor Cells ◽  
Pancreatic Progenitor ◽  
Pancreatic Progenitor Cells ◽  
Proliferation And Differentiation ◽  
Differentiation And Proliferation

Pancreatic progenitor cells (PPCs) are the primary source for all pancreatic cells, including beta-cells, and thus the proliferation and differentiation of PPCs into islet-like cell clusters (ICCs) opens an avenue to providing transplantable islets for diabetic patients. Meanwhile, mesenchymal stem cells (MSCs) can enhance the development and function of different cell types of interest, but their role on PPCs remains unknown. We aimed to explore the mechanism-of-action whereby MSCs induce the in vitro and in vivo PPC/ICC development by means of our established co-culture system of human PPCs with human fetal bone marrow-derived MSCs. We examined the effect of MSC-conditioned medium on PPC proliferation and survival. Meanwhile, we studied the effect of MSC co-culture enhanced PPC/ICC function in vitro and in vivo co-/transplantation. Furthermore, we identified IGF1 as a critical factor responsible for the MSC effects on PPC differentiation and proliferation via IGF1-PI3K/Akt and IGF1-MEK/ERK1/2, respectively. In conclusion, our data indicate that MSCs stimulated the differentiation and proliferation of human PPCs via IGF1 signaling, and more importantly, promoted the in vivo engraftment function of ICCs. Taken together, our protocol may provide a mechanism-driven basis for the proliferation and differentiation of PPCs into clinically transplantable islets.

Designing and Engineering Stem Cell Niches

MRS Bulletin ◽  
2010 ◽  
Vol 35 (8) ◽  
pp. 591-596 ◽  
Author(s):  
Ana I. Teixeira ◽  
Ola Hermanson ◽  
Carsten Werner
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Biology ◽  
Chemical Engineering ◽  
Polyglycolic Acid ◽  
Differentiated Cells ◽  
Extracellular Matrix Components ◽  
Stem Cell Niches

AbstractStem cells have received a lot of attention due to great promises in medical treatment, for example, by replacing lost and sick cells and re-constituting cell populations. There are several classes of stem cells, including embryonic, fetal, and adult tissue specific. More recently, the generation of so-called induced pluripotent stem (iPS) cells from differentiated cells has been established. Common criteria for all types of stem cells include their ability to self-renew and to retain their ability to differentiate in response to specific cues. These characteristics, as well as the instructive steering of the cells into differentiation, are largely dependent on the microenvironment surrounding the cells. Such “stem cell friendly” microenvironments, provided by structural and biochemical components, are often referred to as niches. Biomaterials offer attractive solutions to engineer functional stem cell niches and to steer stem cell state and fatein vitroas well asin vivo. Among materials used so far, promising results have been achieved with low-toxicity and biodegradable polymers, such as polyglycolic acid and related materials, as well as other polymers used as structural “scaffolds” for engineering of extracellular matrix components. To improve the efficiency of stem cell control and the design of the biomaterials, interfaces among stem cell research, developmental biology, regenerative medicine, chemical engineering, and materials research are rapidly developing. Here we provide an introduction to stem cell biology and principles of niche engineering and give an overview of recent advancements in stem cell niche engineering from two stem cell systems—blood and brain.

scholarly journals Platelet-Derived Growth Factor Receptor Alpha as a Marker of Mesenchymal Stem Cells in Development and Stem Cell Biology

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Ramin M. Farahani ◽  
Munira Xaymardan
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Stem Cell ◽  
Cell Biology ◽  
Growth Factor Receptor ◽  
Stem Cell Marker ◽  
Factor Receptor Alpha ◽  
Lines Of Evidence

Three decades on, the mesenchymal stem cells (MSCs) have been intensively researched on the bench top and used clinically. However, ambiguity still exists in regard to their anatomical locations, identities, functions, and extent of their differentiative abilities. One of the major impediments in the quest of the MSC research has been lack of appropriatein vivomarkers. In recent years, this obstacle has been resolved to some degree as PDGFRαemerges as an important mesenchymal stem cell marker. Accumulating lines of evidence are showing that the PDGFRα+cells reside in the perivascular locations of many adult interstitium and fulfil the classic concepts of MSCsin vitroandin vivo. PDGFRαhas long been recognised for its roles in the mesoderm formation and connective tissue development during the embryogenesis. Current review describes the lines of evidence regarding the role of PDGFRαin morphogenesis and differentiation and its implications for MSC biology.

scholarly journals Advances and Applications in Stem Cell Biology

2012 ◽  
Vol 46 (2) ◽  
pp. 75-80
Author(s):  
Shamoli Bhattacharyya
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Biology ◽  
Adult Stem Cells ◽  
Great Promise ◽  
Stem Cell Biology ◽  
Self Renewal ◽  
Main Challenge ◽  
Basic Biology

ABSTRACT Mesenchymal stem cells have shown great promise as the source of adult stem cells for regenerative medicine. Present research efforts are directed at isolating these cells from various sources, growing them in vitro and maintaining their pluripotency as well as capacity for self renewal. It is crucial to identify the regulatory molecules which directly or indirectly control the proliferative status or influence the niche microenvironment. The main challenge is to understand the basic biology of the stem cells and manipulate them for further therapeutic applications. Considering their malignant potential, stem cells may be a double edged sword. While the benefits of these cells need to be harnessed judiciously, a significant amount of research is required before embarking on widespread use of this tool for the benefit of humanity. How to cite this article Bhattacharyya S. Advances and Applications in Stem Cell Biology. J Postgrad Med Edu Res 2012;46(2):75-80.

scholarly journals Transcriptomically-guided mesendoderm induction of human pluripotent stem cells using a systematically defined culture scheme

2019 ◽  
Author(s):  
Richard L Carpenedo ◽  
Sarah Y Kwon ◽  
R Matthew Tanner ◽  
Julien Yockell-Lelièvre ◽  
Chandarong Choey ◽  
...  
Keyword(s):  
Stem Cells ◽  
Pluripotent Stem Cells ◽  
Cell Biology ◽  
Disease Modeling ◽  
Human Pluripotent Stem Cells ◽  
Endoderm Differentiation ◽  
Prolonged Differentiation ◽  
Defined Culture

SummaryHuman pluripotent stem cells (hPSCs) are an essential cell source in tissue engineering, studies of development, and disease modeling. Efficient, broadly amenable protocols for rapid lineage induction of hPSCs are of great interest in the stem cell biology field. We describe a simple, robust method for differentiation of hPSCs into mesendoderm in defined conditions utilizing single-cell seeding (SCS) and BMP4 and Activin A (BA) treatment. Gene sets and gene ontology terms related to mesoderm and endoderm differentiation were enriched after 48 hours of BA treatment. BA treatment was readily incorporated into existing protocols for chondrogenic and endothelial progenitor cell differentiation. After prolonged differentiation in vitro or in vivo, BA pre-treatment resulted in higher mesoderm and endoderm levels at the expense of ectoderm formation. These data demonstrate that SCS with BA treatment is a powerful method for induction of mesendoderm that can be integrated into protocols for mesoderm and endoderm differentiation.

Dynamic effects of Fto in regulating the proliferation and differentiation of adult neural stem cells of mice

2019 ◽  
Vol 29 (5) ◽  
pp. 727-735 ◽  
Author(s):  
Yuhang Cao ◽  
Yingliang Zhuang ◽  
Junchen Chen ◽  
Weize Xu ◽  
Yikai Shou ◽  
...  
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Neuronal Development ◽  
Conditional Knockout ◽  
Biological Processes ◽  
Adult Neural Stem Cells ◽  
Proliferation And Differentiation

Abstract N 6-methyladenosine (m6A) modification of RNA is deposited by the methyltransferase complex consisting of Mettl3 and Mettl14 and erased by demethylase Fto and Alkbh5 and is involved in diverse biological processes. However, it remains largely unknown the specific function and mechanism of Fto in regulating adult neural stem cells (aNSCs). In the present study, utilizing a conditional knockout (cKO) mouse model, we show that the specific ablation of Fto in aNSCs transiently increases the proliferation of aNSCs and promotes neuronal differentiation both in vitro and in vivo, but in a long term, the specific ablation of Fto inhibits adult neurogenesis and neuronal development. Mechanistically, Fto deficiency results in a significant increase in m6A modification in Pdgfra and Socs5. The increased expression of Pdgfra and decreased expression of Socs5 synergistically promote the phosphorylation of Stat3. The modulation of Pdgfra and Socs5 can rescue the neurogenic deficits induced by Fto depletion. Our results together reveal an important function of Fto in regulating aNSCs through modulating Pdgfra/Socs5-Stat3 pathway.

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